The neutron emission in projectile fragmentation at relativistic energies was studied with the Large-Area-Neutron-Detector LAND coupled to the ALADIN forward spectrometer at the GSI Schwerionen-Synchrotron (SIS). Stable 124Sn and radioactive 107Sn and 124La beams with an incident energy of 600 MeV/nucleon were used to explore the N/Z dependence of the identified neutron source. A cluster-recognition algorithm is applied for identifying individual particles within the hit distributions registered with LAND. The obtained momentum distributions are extrapolated over the full phase space occupied by the neutrons from the projectile-spectator source. The mean multiplicities of spectator neutrons reach values of up to about 11 and depend strongly on the isotopic composition of the projectile. An effective source temperature of T \approx 2-5 MeV, monotonically increasing with decreasing impact parameter, is deduced from the transverse momentum distributions. For the interpretation of the data, calculations with the statistical multifragmentation model were performed. The variety of excited projectile spectators assumed to decay statistically is represented by an ensemble of excited sources with parameters determined previously from the fragment production observed in the same experiments. The obtained agreement is very satisfactory for more peripheral collisions where, according to the model, neutrons are mainly emitted during the secondary decays of excited fragments. The neutron multiplicity in more central collisions is underestimated, indicating that other sources besides the modeled statistical breakup contribute to the observed neutron yield. The choice made for the symmetry-term coefficient of the liquid-drop description of produced fragments has a weak effect on the predicted neutron multiplicities.

The ASY-EOS experiment at GSI laboratory measured the direct and elliptic flow of neutrons and light charged particles in the reaction 197Au+197 Au at 400 A MeV incident energy. The ratio of elliptic flow of neutrons with respect to that of the light charged particles was used as main experimental observable to probe the density dependence of the symmetry energy term of the nuclear equation of state. Results, obtained by comparison of the experimental data with the UrQMD model predictions, strongly support a moderately soft to linear density dependence of the symmetry energy at suprasaturation densities below 2ρ0.

In the ASY-EOS experiment flows of neutrons and light charged particles were measured for 197Au+197Au collisions at 400 MeV/nucleon, in order to investigate the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. By comparing the experimental data with the UrQMD transport model predictions, we have extracted a new constraint in agreement with the moderately soft to linear density dependence obtained in the former analysis on FOPI-LAND data, but reducing the associated uncertainty by a factor ∼ 2.

Directed and elliptic flows of neutrons and light charged particles were measured for the reaction 197Au+197Au at 400 MeV/nucleon incident energy within the ASY-EOS experimental campaign at the GSI laboratory. The detection system consisted of the Large Area Neutron Detector LAND, combined with parts of the CHIMERA multidetector, of the ALADIN Time-of-flight Wall, and of the Washington-University Microball detector. The latter three arrays were used for the event characterization and reaction-plane reconstruction. In addition, an array of triple telescopes, KRATTA, was used for complementary measurements of the isotopic composition and flows of light charged particles. From the comparison of the elliptic flow ratio of neutrons with respect to charged particles with UrQMD predictions, a value \gamma = 0.72 \pm 0.19 is obtained for the power-law coefficient describing the density dependence of the potential part in the parametrization of the symmetry energy. It represents a new and more stringent constraint for the regime of supra-saturation density and confirms, with a considerably smaller uncertainty, the moderately soft to linear density dependence deduced from the earlier FOPI-LAND data. The densities probed are shown to reach beyond twice saturation.

The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. In the ASY-EOS experiment at the GSI laboratory, flows of neutrons and light charged particles were measured for 197Au+197Au collisions at 400 MeV/nucleon. Flow results obtained for the Au+Au system, in comparison with predictions of the UrQMD transport model, confirm the moderately soft to linear density dependence of the symmetry energy deduced from the earlier FOPI-LAND data.

Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (πN) TDAs from \(\bar pp \to e^ + e^ - \pi ^0 \) reaction with the future P̄ANDA detector at the FAIR facility. At high center-of-mass energy and high invariant mass squared of the lepton pair q 2, the amplitude of the signal channel \(\bar pp \to e^ + e^ - \pi ^0 \) admits a QCD factorized description in terms of πN TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring \(\bar pp \to e^ + e^ - \pi ^0 \) with the P̄ANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. \(\bar pp \to \pi ^ + \pi ^ - \pi ^0 \) were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q 2 < 4.3 GeV2 and 5 < q 2 GeV2, respectively, with a neutral pion scattered in the forward or backward cone \(\left| {\cos \theta _{\pi ^0 } } \right| > 0.5\) in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the P̄ANDA detector will allow to achieve a background rejection factor of 5 · 107 (1 · 107) at low (high) q 2 for s = 5 GeV2, and of 1 · 108 (6 · 106) at low (high) q 2 for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 fb−1 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with P̄ANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing π TDAs.

A simple method to reduce the background from secondary reactions in telescopes composed of long CsI(Tl) crystals is presented. The method has been developed for the KRATTA [1] modules.

Inverse kinematics scattering of 18O on 6Li at Elab(18O) = 114 MeV was measured to obtain elastic and inelastic scattering cross sections. In this way cross sections for excited states in 6Li and 18O were determined. The data were analyzed within the optical model and coupled reaction channel method. The 6Li + 18O optical potential as well as the 6Li and 18O deformation parameters were deduced. Contributions of different nuclear processes to the 6Li + 18O elastic and inelastic scattering were explored. The isotopic differences between the 6,7Li + 18O and 6Li + 16,18O potential parameters were determined.

Angular distributions of the 6Li(1 170)7Li reaction were measured at Eiab (1 80,) = 114 MeV for ground and excited states of the exit channel nuclei for the first time. The data were analyzed within the coupled-reaction-channels method (CRC). The 6Li + 180 elastic and inelastic scattering channels as well as simplest one- and two-step reactions were included in the coupled-reaction-channels scheme. The 7Li + 170 potential was deduced by fitting CRC calculations to the reaction data. The spectroscopic amplitudes for single nucleon and nuclear cluster configurations were calculated within the translationally invariant shell model. Isotopic differences of the 7Li + 16, 17, 180 and 7'81,i+ 170 potentials and the reaction mechanisms were studied. (C) 2014 Elsevier B.V. All rights reserved.

Complete angular distributions of the 14C + 11B elastic and inelastic scattering at the energy \( E_{lab}({}^{11}B)\) = 45 MeV were measured for the ground and excited states of 11B. The data were analyzed within the optical model and the coupled-reaction-channels method. The parameters of the 14C + 11B optical potential and 11B deformation were deduced. The contributions of one- and two-step transfers of nucleons and clusters into the 14C + 11B elastic and inelastic scattering were calculated. The isotopic differences between the 14C + 11B and 12,13C + 11B scatterings are presented and clearly show the importance of the large angle scattering data for understanding the interaction between light heavy ions.

New experimental data for differential cross sections of the 14С(11B, 9Be)16N reaction were measured for the ground states of 9Be and 16N nuclei as well as for the excited states of 16N at the energy Elab.(11В) = 45 MeV. The reaction data were analyzed within the coupled-reaction channels method (CRC) for one- and two-step transfers of nucleons and clusters. In the CRC-calculations, the optical potential deduced from the analysis of the 11В + 14С elastic scattering data was used for the entrance reaction channel. Needed spectroscopic amplitudes of nucleons and clusters in nuclei were calculated within shell-model. 9Ве + 16N optical potential parameters were deduced by fitting CRC cross-sections to the 14С(11B, 9Be)16N reaction data. Contributions of one- and two-step transfers of nucleons and clusters into the 14С(11B, 9Be)16N reaction cross-sections were obtained.

This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.

This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the \(\overline{P}\)ANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole \(\overline{P}\)ANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.

KRATTA, a new, low threshold, broad energy range triple telescope array has been built to measure the energy, emission angles and isotopic composition of light charged reaction products. It has been equipped with fully digital chains of electronics. The array performed very well during the ASY-EOS experiment, conducted in May 2011 at GSI. The structure and performance of the array are presented using the first experimental results.

Angular distributions of the 7Li + 12C elastic and inelastic scattering as well as the 7Li(14N, Х) reactions with exited stable and unstable nuclei with Z = 3 6 were measured at Elab(12C) = 115 MeV. The data were analyzed within the optical model and coupled-reaction-channels method. The elastic and inelastic scattering, reorienta-tions of 7Li in ground and excited states as well as more important transfer reactions were included in the chan-nels-coupling-scheme. 7Li + + 12C optical potential parameters for ground and excited states of 7Li and 12C as well as deformation parameters of these nuclei were deduced. The contributions of one- and two-step transfers in the 7Li + 12C elastic and inelastic scattering channels were estimated.

The performance of the LAND neutron detector is studied. Using an event-mixing technique based on one-neutron data obtained in the S107 experiment at the GSI laboratory, we test the efficiency of various analytic tools used to determine the multiplicity and kinematic properties of detected neutrons. A new algorithm developed recently for recognizing neutron showers from spectator decays in the ALADIN experiment S254 is described in detail. Its performance is assessed in comparison with other methods. The properties of the observed neutron events are used to estimate the detection efficiency of LAND in this experiment.

Angular distributions of the 6Li + 18O elastic and inelastic scattering as well as the 6Li(18O, Х) reactions with production of 16,17,19O + 8,7,5Li, 14,15,16,17N + 10,9,8,7Be and 12,13,14C + 12,11,10B nuclei were measured at Elab(18O) = = 114 MeV. The data were analyzed within the optical model and coupled-reaction-channels method. The 6Li + 18O optical potential parameters as well as deformation parameters of these nuclei were deduced and the scatter-ing mechanisms were studied. The isotopic differences between the 6, 7Li + 18O and 6Li + 16, 18O scattering as well as their potential parameters were investigated.

Angular distributions of the 6Li(18O, 17O)7Li reaction were measured at Elab(18O) = 114 MeV for ground and excited states of exit nuclei. The data were analyzed within the coupled-reaction-channels method (CRC). The 6Li + 18O elastic and inelastic scattering channels as well as the simplest one- and two-step reactions were includ-ed in the coupled-reaction-channels scheme. In CRC calculations, the 6Li + 18O potential with parameters de-duced from the elastic scattering data, was used for the entrance reaction channel. The spectroscopic amplitudes of nucleons and clusters were calculated within the translational-invariant shell model. The 7Li + 17O potential parameters were deduced by fitting 6Li(18O, 17O)7Li reaction data. Isotopic differences of the 7Li + 17O, 7Li + 18O and 7Li + 16O potential, as well as the reaction mechanisms are studied.

This document illustrates the technical layout and the expected performance of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect charged particles as close as possible to the interaction zone. Design criteria and the optimisation process as well as the technical solutions chosen are discussed and the results of this process are subjected to extensive Monte Carlo physics studies. The route towards realisation of the detector is outlined.

Angular distributions of the 7Li + 14N elastic and inelastic scattering as well as the 7Li(14N, Х) reactions with production of 13, 15, 16N + 8, 6, 5Li, 11, 12, 13, 14С + 10, 9, 8, 7Ве, 10, 11, 12В + 11, 10, 9В nuclei and others were measured at Elab (14N) = 80 MeV. The data were analyzed within the optical model and coupled-reaction-channels method. The elastic and inelastic scattering, reorientations of 7Li and 14N in ground and excited states as well as the prominent one- and two-step transfers were included in a channels-coupling-scheme. The 7Li + 14N optical potential parameters for ground and excited states of 7Li and 14N as well as deformation parameters of these nuclei were deduced. The contributions of one and two-step transfers in the 7Li + 14N elastic and inelastic scattering channels were estimated.